Stress corrosion cracking growth rate prediction model for nuclear power turbine rotor steel in a simulated environment

Abstract

Considering the electrochemical reaction and chemical reaction near the crack in the local corrosion environment, the stress corrosion cracking growth rate prediction model for nuclear power turbine rotor steel was established based on the slip dissolution mechanism and finite element method. The calculated parameters were defined based on the material and electrochemical properties of steam turbine rotor in the simulated environment, and the calculated results can agree well with the experiment results. Results revealed that the stress intensity factor has an important influence on the local corrosion environment at the crack tip, the electrode potential is decreased and the process of anodic dissolution is accelerated with the increase of the stress intensity factor. Furthermore, the prediction model can describe stage-I and stage-II of stress corrosion cracking propagation well, and provide a possible trend prediction for practical production practice.